Hospital acquired infections such as ventilator-associated pneumonia (VAP) are a serious medical concern and a leading cause of death among hospital patients. Such infections often are caused by aspiration of oral or gastric secretions which can convey harmful bacteria to a patient's lungs. Subglottic secretions which accumulate above an endotracheal tube cuff are a major source of infection in mechanically ventilated patients.
It is often desirable to institute continuous aspiration of subglottic secretions using a specialized endotracheal tube with separate dorsal suction lumen to remove oral and/or gastric secretions from above the endotracheal tube cuff before they are aspirated. An illustrative embodiment of an endotracheal tube having a subglottic evacuation lumen is described with reference to FIG. 1. The endotracheal tube 100 includes a ventilator tube portion 102, a cuff 104 and a cuff inflation valve 106 for inflating the cuff 104. A subglottic tube 108 includes suction lumen 109 incorporated with the endotracheal tube 100 for continuous aspiration of subglottic secretions through an evacuation port 110 above the cuff 104.
Vacuum is often applied to the subglottic tube through a standard hospital vacuum regulator. However, the use of standard hospital vacuum regulators is accompanied by drawbacks and disadvantages. In general terms, use of current vacuum regulators does not generally yield adequate flow of air at the typical range of vacuum levels associated with such devices.
Standard hospital vacuum regulators also do not typically include flow indicators suitable for recognizing blockage of the subglottic tube. Medical personnel often visually check the subglottic tube for small amounts of secretions every few hours. If blockages are suspected, the medical personnel are generally required to disconnect the subglottic tube from the standard hospital regulator and administer a bolus of air to the tube using a syringe, for example. Each disconnection and reconnection of the subglottic tube greatly increases the chances of bacterial contamination leading to dangerous infection.
Also, disadvantageously, the use of a standard hospital vacuum regulator for subglottic aspiration reduces the availability of vacuum sources for various other suction procedures that are often necessary. The use of a standard hospital vacuum regulator also takes up available space between other gas supply outlets (i.e. oxygen, air) which is typically limited in a hospital environment.